Data encryption is ubiquitous. Files, segments, and entire hard drives are often encrypted in order to protect the data on those media. In general, disk encryption is done using a symmetric key. The symmetric key is only known to the data owner. The owner can be sure that no one else can access the data, unless the data owner provides them the symmetric key. However, this has numerous problems. First, the user must share the symmetric key in order to allow access to the resource by another person. Furthermore, it is difficult for administrators since the user for whom a device is to be provisioned must be there, or the symmetric key must be sent to the user which is a security risk.